PWM outputs opperate differetly

[masrellim]

I am running a V570, v200-18-E5B, and IO-D16A3-TO16.  the high speed outputs on the snap in and the expansion are both running identical stepper motor drives and motors.  the motor that is controlled by the snap in has a long lag between button push and when it starts moving.  It will not run at a constant speed and some times even stops and restarts with the button still pressed.  the motor that is controlled by the expansion runs at a constant speed, stops and starts immediately with button commands, and runs must faster than the snap in controlled motor.  stepper motor drives are set up the same (smooth 400, ect).  the only difference between the 2 motors is the length of wire between the out puts and the motor drives.  the snap in wire is 14' long and the expansion wire is about 2' long.   Any ideas on how to smooth out the operation of the motor that is controlled by the snap in? 

CB v14 EOB 5-29.vlp

[Flex727]

I'd love to look at your .vlp file in depth (thanks for including it, by the way), but I'm a bit bogged down at the moment. Let me suggest this until someone else can come along to help (or I can crawl out from under my deluge of work). Swap the wiring between the motors and/or swap the outputs in the program to try isolating the source of the problem and see what you get.

[masrellim]

I have tried most everything mechanical / hardware that I can think of to  isolate the difference in performance.  I have tried 3 different motors (4wire, 8 wire series , 8wire parallel).  I have tried all the adjustment on the motor drives (type of motor, steps per rev, ect).  I have 3 other machine that run the same snap in and I have switch the snap in with other machines. every thing I have tried leads back to 3 things.  length/type of wire between output and motor drive, a difference in how the snap in and expansion outputs work, or I have a difference in the programing of the 2 outputs that I can not see.  I have not tried to shorten the distance between the motor drive and the snap in, so that is on my list of things to try today.  this test will at least remove the variable of length.   

[Flex727]

2 minutes ago, masrellim said:

leads back to 3 things.  length/type of wire between output and motor drive, a difference in how the snap in and expansion outputs work, or I have a difference in the programing of the 2 outputs that I can not see.

It would be easier to lengthen the shorter wire than shorten the longer wire, no?

Also, swap the Outputs in the program - just do a search and replace (thrice, move one set to a parking place, then move the other set, then move the parked outputs). This would be easier if you used buffered outputs.

That should point to or eliminate the last 2 of the 3 remaining options.

[masrellim]

tried every thing above and did not make a difference. So for fun I swapped out the v560 hmi for a v260 that was running a motor just fine on a similar machine.  After the swap out motor ran just fine.  So now my question would be what is the difference between a 560 and 260. 

[Flex727]

That's interesting, I've never encountered a V260. Is that a Vision, or Enhanced Vision PLC?

When you say "did not make a difference", are you saying the same motor still had the problem even when you switched outputs or switched wiring? Or did the problem move with the switch?

When you say you swapped out a V260 for the V560, are you using the same Snap-In I/O module after the swap?

[masrellim]

it is a vision oplc.  we have 3 machine that us it.  the machine I am working on was going to have it but apparently it is now unavailable and i was directed to the v560 as it was the same size as the v260, had color screen, and was touch.

what I mean by "did not make a difference" is that the problem stays with the output.  No matter what motor/drive I connect or how I connect them to the outputs on the snap in the motors run inconstant.

I removed only the v560 hmi.  all other hardware stayed the same.     

[Ofir]

Hi,

Please check the frequency.

I'm not near my PC now but if I'm not wrong the units of the frequency when using V260 is 1Hz and when using the V560 is 0.1Hz. 

[Joe Tauser]

First, thank you for posting your code in your initial post.

The V260 is an older model using the Standard Instruction set.    It's like a V230 or V280.  

The V560 uses the Enhanced Instruction set and can be a different animal, especially on motion control.

I looked at the code you posted on May 30 and saw O0 on the E5B is configured for PWM as well as O 96 on the TO16 module.  You are powering up your duty cycle on both to 0 and then storing 900 to them in net 10 of the outputs subroutine.  I'm surprised this works at all.  Set the power-up value for MI 17 and MI 27 to 500 (50%) and delete net 10.

You may want to read the Help on the Stepper Control tab for the E5B.  It was not available on the V260 and is actually much easier to use if you are using the stepper for positioning.

Joe T.